US: Blackberries and vertebrate damage at Tunnel Berries
It appears that the protected environment also appealed to a critter (likely a rabbit), who snacked on blackberry bark and girdled many canes. He, she or they preferred the variety Triple Crown over Natchez, Columbia Star or Obsidian. The girdled canes will have to be removed along with a lot of fruit they would have produced this summer.
Source: Tunnel Berries